I have a virtualbox running ubuntu 13.10 (running on a 13.10 host) that has two shared folders on the host that are mounted at boot. A while ago the guest ran some updates that broke the folder sharing, the guest could no longer see the devices to mount them. I had a hunch from reading around that it might be something to do with the guest additions, as getting the 4.3 release of virtualbox from the oracle repo and updating the guest additions solved the problem. The issue is, today's linux headers update broke the mount again, and there doesn't appear to be an updated guest additions to go to! (re-installing them doesn't work).

Obviously at a basic level, not installing the updates would prevent this problem. However I'd be interested in finding out exactly why it's behaving like this.

I'm a bit out of my depth here but if someone could point me in the right direction of a solution I'd appreciate it.

If there's more useful info I can provide let me know.

Full error message I'm now getting when trying to use the manager to mount the Guest Additions CD Image:

Unable to access "VBOXADDITIONS_4.3.4_91027"

Error mounting /dev/sr0 at /media/ptinkler/VBOXADDITIONS_4.3.4_91027: Command-line 'mount -t "iso9660" -o "uheper=udisks2,nodev,nosuid,uid=100,gid=1000,iocharset=utf8,mode=0400,dmode=0500" "/dev/sr0" "/media/maplecroft/VBOXADDITIONS_4.3.4_91027" exited with non-zero exit stats 32: mount: unknown filesystem type 'iso9660'